Antibiogram and virulence profiling reveals multidrug resistantStaphylococcus aureusas the predominant aetiology of subclinical mastitis in riverine buffaloes

Abstract

Background Staphylococcus spp. are the major causal agents of mastitis in dairy animals worldwide leading to profound economic losses and public health threats. Recently, Staphylococcus aureus has emerged as a multidrug resistant and zoonotic pathogen. This study aimed to characterize S. aureus in subclinical mastitis (SCM) milk samples of riverine buffaloes in Bangladesh through antibiogram and virulence gene(s) profiling, and 16S rRNA gene sequencing. Method We characterized S. aureus in SCM milk samples (N = 500) of riverine buffaloes through antibiogram and virulence gene(s) profiling, and 16S rRNA gene sequencing. Results Out of 500 milk samples tested, 188 (37.6%) were found positive for SCM. From 188 SCM samples, 291 isolates were obtained with a prevalence of S. aureus in 37.4% (109/291) isolates. Phylogenetic analysis revealed the evolutionary divergence of S. aureus isolates in bubaline SCM milk samples. The antibiogram profiling showed that about 96.0% S. aureus isolates were multidrug resistant (MDR). Notably, 29 and 16 isolates harboured methicillin‐resistant (mecA) and panton‐valentine leucocidin (pvl) genes, respectively, and 46 plasmid‐bearing isolates were MDR. Nine Staphylococcal enterotoxins (SEs/SEls) including sea (11.9%), sec (7.4%), sed (4.6%), seg (3.7%), and seh (3.7%) were detected with 72.48% toxinotypes comprising a single gene. Conclusion This study therefore suggests S. aureus as the single‐most aetiology (∼37.0%) of SCM in riverine buffaloes, and emergence of MDR, enterotoxin producing, and virulent S. aureus strains could impose potential threats to animal welfare and public health.

Staphylococcus microti Strains Isolated from an Italian Mediterranean Buffalo Herd

“…Our study performed in a buffalo farm determined a statistically significant higher level of IMI (62%) than SCM (11%) cases, with no cases of CM. Several studies have analyzed the prevalence of SCM in buffalo populations around the world, reporting a prevalence of approximately 26.2% and 37.6% in India and Bangladesh, respectively [28,29]. The meta-analysis work conducted by Krishnamoorthy et al [30] on numerous studies published worldwide during the period 1967-2019 has identified values of 46% and 32% for SCM cases in buffaloes worldwide and in India, respectively.…”

Characterization of β-lactamase and virulence genes inPseudomonas aeruginosaisolated from clinical, environmental and poultry sources in Bangladesh

“…The Pearson’s chi-square test was performed to compare the prevalence of P. aeruginosa in three different sample categories (e.g., clinical, environment and poultry). A prevalence percentage was calculated by dividing the number of positive samples for the given category by the total samples tested within that category [29, 30]. The prevalence formula was applied for determining prevalence percentage of Pseudomonas and P. aeruginosa .…”

Review on the Epidemiology, Milk Composition Changes, and Antimicrobial Susceptibility of Causative Agents of Bubaline Mastitis in Asia

“…There are several methods for determining the antimicrobial susceptibility of causative pathogens of bubaline mastitis, such as the disk diffusion method, microdilution assay, and PCR (Clinical Laboratory Standards Institute [CLSI], 2019; Hoque et al, 2022). Disk diffusion method is commonly used to determine the antimicrobial susceptibility causative pathogens of bubaline mastitis in Asia countries because it is simple, reliable, and can detect the isolated resistant colonies (Mayrhofer et al, 2008;Milici et al, 2007).…”

“…Disk diffusion method is commonly used to determine the antimicrobial susceptibility causative pathogens of bubaline mastitis in Asia countries because it is simple, reliable, and can detect the isolated resistant colonies (Mayrhofer et al, 2008;Milici et al, 2007). PCR detected the virulence genes in isolated bacteria (Hoque et al, 2022).…”